Forming device for insulated wire



March 18, 1958 J. T. DUGALL El AL 2,826,782

FORMING DEVICE FOR INSULATED WIRE Filed Nov. 23, 1954 3 Sheets-Sheet 1 FIG. 1. v v s flN T U A L INVENTORS 5 I V cawwazs'M FRE I RICKSON 3%? a E F-Ji%fi FIG. 2.

ATTo ms March 18, 1 J. T. DUGALL ET AK. 3 9

, 4 FORMING DEVICE FOR INSULATED WIRE Filed Nov. 23, 1954 3 Sheets-Sheet 3 I 6 Jo DUG INVENTORS United States Patent FORMING DEVICE FOR INSULATED WIRE John T. Dugall, Charles M. Fredrickson, and Emerson D. Holman, Newark, and Ralph L. Wohlforth, Granville, Ohio, asignors to Kaiser Aluminum 5.; Chemical Corporation, Oakland, Calif., a corporation of Delaware Application November 23, 1954, Serial No. 470,654

6 Claims. (Cl. 18-13) the conductors, wherein the insulating material may be demarked or adhesively joined between the conductors ter assembly positioned across the discharge orifice of the die body;

Figure 4 is a face view of the die body seen in Figure 2 taken along the line 4 4 of Figure 2;

Figure 5 is a face view of the die body taken along: the line 5-5 of Figure 2 and showing the slitter elements and associated knife members correctly positionedon dowel pins 12 and the face of the die body, the re tainer elementbeing removed;

Figure 5A is a cross-section through the type of insulated wiring'or conductor produced by the assembled die elements disclosed in Figures 1, 2 and 5;

Figure 6 is a view of the face of the die when taken along line 6-6 of Figure 3 with the retainer and knife elements showninj Figure 3 positioned on the dowel pins 12 and the face of the die body and across the dis charge orifice thereof; V

Figure 6A is across-sectional view of the conductor produced by the associated elements as shown assembled in Figures 3 and 6 as the insulation and conductors pass through the dischargeorificey in such, a manner that the conductors may be readily separated at the terminal ends of the wire.

Accordingly, it is an object of this invention to provide a novel extruding die wherein a variety of types'of insulated wire may be produced while employing a single die body.

It is a further object of this invention to provide a novel-extruding die including a retainer and slitter or knife assembly provided with interchangeable parts whereby the same die body may be used to produce covered conductors of varied forms.

It is a further object of theinvention to provide an extruding die used in the production of insulated wiring wherein the die may be converted for the production of more than one form of insulated Wire and wherein such conversion may be made without removal of the die body as a whole from the extruding machine, and wherein the conversion may be made with ease and convenience.

A further object of the invention is the production of a die having an interchangeable end or retainer and slit ter assembly capable of producing covered conductors of at least three substantially different forms or crosssections. In the one form, the insulation may be left undisturbed, in a second form, the conductor insulation is weakened between the individual conductor members such that it may be readily severed upon a lateral force being exerted on the insulating material. In still another form, the insulation is completely severed between the conductor members and subsequently joined by a relatively weak adhesive connection after the wire and insulating material have passed through the die body and associated knife elements, this latter type being known in the conductor art as double D insulated wire.

The above mentioned and other features and objects of this invention will become more'apparent andthe invention itself will be best understood by reference to Figure 7 is a view of the retainer element taken along the line 7-7 of Figure 2;

Figure 8 is a view of the retainer element taken along;

the line 88 ofFigure 3;

Figure 9' is a perspective view of the knife element:

used in the embodiment of the invention disclosed in: Figure3;

Figure 10 is a perspective view of one of the knife holders usedin the embodiment of the invention as 1 shown in particular in Figure 5;

the following detailed description taken in conjunction with the accompanying drawings, wherein:

Figure l is a plan sectional view of an extruding tip and die body including one embodiment of the retainer and slitter assembly of the instant invention, with the aforesaid elements being located in an extruding chamber of a conventional screw-feed extruding machine,

the latter of which is diagrammatically shown;

Figure 2 is an elevational section of Figure 1, when taken along line 2-2 thereof showing the retainer and 1 associated slitter assembly positioned across the discharge orifice of a die body;

Figure 2, but showing a second form of retainer and slit- Figure 11 is a view similar to Figure 10 showing the form of theknife holder used in the embodiment of the invention disclosed in Figure 3.

With particular reference to the drawings and particu' larly Figs. 1, 2, 3 and Figure 4 thereof, the device of. the instant'invention includes. an extrusion tip 1, an as-' sociated die body member 2, these members being sup ported in, the usual spaced relation to one another in ,a

,, conventional extruding machine die body chamber desig- This space is provided between the die body member 2 and the nozzle of the tip memher 1, the latter of which has suitable apertures 5 andnated generally as 3'.

ciated members 1 and 2 which force it to flow in compact adhesion relation around the conductor members 20 and 21. The extruding nozzle 1 may be of a com ventional design wherein the conductor members 20 and 21 pass through an open end disposed outside' the chamber and are guided by apertures 5 and 6 in spaced par-ah lel relation and in alignment with an orifice in the die; body for the' purposes which will be hereinafter de scribed.

In an advantageous embodiment of the invention, the die body 2 comprises a smoothly machined, generally cylindrical-like member, which is anchored by any suitable means in the wall 3 of the extruding machine 3.,

This cylindrical member has a generally funnel-shaped bore 11 as seen in Figs. 1, 2 and 3 extending from its inner face toward its discharge end as viewed in these figures. The bore 11 terminates at its smaller end, hereinafter called the discharge end, in an orifice 7,' which may be clearly seen in Fig. 4, said discharge orifice being generally oval in'configuration and being aligned with the small end of the extruding nozzle or tip 1 as is clearly f shown in Figs. 1,-2'and 3.

The outer or discharge face 2' of the die body 2, as viewed in Fig. 4-, is generally a-plane surface having horizontally extending axially aligned recesses as shown by reference numerals .15 and 16, these recesses being of considerable width relative to the sides of'the oval aperture or orifice 7 and extending from the edges of the aperture laterally outwardly to either side thereof across the entire face of the die body to the marginal edges thereof. Located within the region embraced by the recesses are suitable dowel. pins 12 which are used for a purpose to be hereinafter described. The die body 2 is also provided with other apertures 14 which receive machine screws for a purpose which will also be hereinafter described. As may be seen in Figs. 1 and 2, the recess portions 15 and 16 of the die face 2' extend generally parallel with respect to a horizontal plane when the die, body 2 is properly positioned in the end wall 8 of the extruding machine 3.

Referring in particular to Figs. 1, 2, and 7, along with Fig. 10, there are shown the removable components which make up one form of replaceable retainer and slitter assembly for producing the type of covered conductor wire shown in cross-section in Fig. 5A. These components comprise a retainer member 30, said memher being also preferably cylindrical in form and having parallel faces or ends, the retainer member 30 having a central aperture 31 of rightly figure 8 outline and adapted to be fixed to the die body with the orifice 7 of the die body 2 aligned with the aperture 31 in the retainer member 30. Retainer member 30 is bored as at 35 with apertures adapted to receive machine screws 45 which pass through these apertures as shown in Figs. 1 and 2, and are threadedly engaged with the die body 2 to maintain the retainer member 30 in fixed relation with respect thereto.

Referring now to Fig. 5 in particular the die body 2 is shown with one form of slitter assembly attached to the face thereof. As may be seen. from Fig. 5, in this form the slitter assembly comprises a pair of similarly constructed knife holders 70 and 71 installed in the recesses 15, 16 provided in the face 2 of the die body 2. Holders 70 and 71 have apertures 75 therein which are adapted to be placed in alignment with the dowel pins 12 on the face of die body 2, such that the dowel pins will pass through the apertures 75 so as to maintain these elements in proper relation with respect to each other. The .knife holders 70, 71 include pointed portions 78, 79 respectively, which extend inwardly of and across 'the midde portion of the dischargeorifice 7 in die body 2 so as to divide the orifice into a generally figure S-shaped outline. Apair of spring steel knives 60 and 61 are in turn inserted in the slots 72 which extend longitudinally of the knife holders 70 and 71. Thus, it may be seen that with the slitter assemblage in place on the face of the die body 2, the retainer member as shown in Fig. 7 and identified as member 30 is aligned with the knife holders 70 and 71 in such a way that it bears against the forward edge of the knife elements 60 and 61 while the. knife holders 70 and 71 receive the rearward edges of the knives 60 and 61 and the entire slitter assemblage is fixed in non-rotative relationship with respect to the die body 2. Machine screws 45 are then inserted in apertures 35 in the retainer 30 from whence they pass into the threaded apertures 14 in the die body so as to securely lock the retainer member 30, knife holders 70 and 71, and knife elements 60 and 61 in place on the face 2' of the die body 2. Thus, it may be seen from a comparison of Fig. 5 with Fig. 4, that the generally elongated oval aperture 7 has now assumed a generally figure 8 outline. As the insulated or covered conductors pass through the aperture 7, and between knife holders 70, 71 and knives 60 and 61, the insulating material extruded in close adhesive relation on the conductors 20, 21 will contact the knife elements 60 and 61 and retainers 70 and 71., As a result, the extruded insulation or covering for the conductors will be shaped into the cross-section illustrated in Fig. 5A. It is to be noted that in an advantageous embodiment of the invention, the knife elements 60 and 61 may be adjusted laterally across the face of the die body and in more or less abutting relation in the slots provided in the knife holders 7t! and 71 by simple manual adjustments and by merely loosening to a minor degree the machine screws 45. Thus, it may be seen that the connecting web 160 for the conductor covering 100' as shown in Fig. 5 may be varied in thickness in such a manner that any desired amount of insulating material may be retained between the two conductor members 20 and 21. by the use of only one set of knife elements.

Referring now in particular to Figs. 3, 8, 6 and 6A, as well as Fig. 11, a second embodiment of the novel insulation forming and cutting device of the instant invention is disclosed. As will be seen from a review of these figures, the elements comprising the retainer member, knives and knife holders, previously described, are completely removed from the face of the die body 2. In place thereof there is substituted a novel knife element 50 as clearly shown in Figs. 9 and 11 of generally shallow T- shaped form having its base leg or stem 50' of substantially the same horizontal Width as the lateral edges of the aperture 7 in die body 2. A pair of knife holders 55 of identical configuration and including properly spaced apertures 54 to coincide with the dowel pins.12 in the face 2' of the die body 2 are inserted in the recesses 15, 16 previously described. As shown in Fig. 11, these elements are also provided with generally longitudinal elongated slots 52 similar to the slots 72 in holders 70, 71. As may be seen from an inspection of Figs. 6 and 3, the knife holders 55 are placed in the recesses 15 and 16 provided in the face 2' of the die body 2 such that the slotted portions 52 thereof are in alignment across the face 2' of the die body 2. The wings of the spring steel knife element 50 are then inserted in the slots 52 of the knife holders and extends across the aperture 7 substantially mid-way between the upper and lower walls thereof, with the arms or wings of the T extending into the slots 52 of the aligned holder elements 55. The stem 50' of the T-shaped knife is provided with a cutting edge 51'. Thus, it may be seen that when installed in proper relation with respect to the die body 2, the knife element 50 will serve to slit or separate any material which is passed through the aperture 7.

A suitable retainer member 40 for the above described knife and knife holders is disclosed in Figs. 3 and 8 for use with the form of knife now under consideration. This retainer member 40 has apertures 41 located in generally symmetrical and circumferential relation with respect to the center of the retainer member 40. These apertures are arranged similarly to the apertures 14 provided in the face 2' of the die body 2 and in turn receive the machine screws 45. These screws are adapted to pass therethrough into the face 2' of the die body 2 in screw threaded relation therewith. Thus, it may be seen that uponlthe application of the screws 45, the retainer 40 as well as the knife holders 55 and the knife element 50 will be fastened in rigid relation with respect to the die body 2. Again dowel pins 12 pass through suitable apertures, in this case 51 of the holder elements 55, to position the holders in proper relation with orifice 7 of die body 2 and with respect to recesses '15 and 16. Referring in particular :to Fig. 8, the retainer bears against the knife 50 and as the screws are tightened, clamps the knife element into firm engagement with members 55, whereby the knife element is restrained from any motion whatsoever. Referring to Fig. 6, the knife element 50 is shown in position across the face of the die body with the knife holders 55 in proper relation within the recesses 15,. 16 provided in the face of the die body 2. As seen in Fig. 6 and Fig. 3, the knife 59 also has a notch-like recess .57 across the edge thereof located centrally of the discharge bore 47 of the retainer element 40.. If desired,

. this slot may be vented to the outside air whereby as the insulating material passes thereover, air will beintroduced between the strips of insulating material cut by the knife 50 so as to form a pocket of air between the strips after they are again brought together in a manner to be de; 5 e e na -s Th s o k to airi turn d n helping to pry the two pieces of insulated cablecovering apart during usage of the same. With reference to the form of the invention now under consideration, attention is directed to Figs. 6 and 6A which show the insulated 10 material formed into what is known as double D insulated wiring when the material appears as it would immediately after its passage over the knife member 50 and also that the discharge aperture 47 in retainer 40 is identical with the bore 7 indie body 2.

With reference to Fig. 3, the naturaltension induced in the conductors as they pass beyond the slitter is sufficient to cause the separated surfaces of the insulation to touch in adhesive relation, and due to the tacky nature of the insulating material, they will remain in this position. Upon subsequent curing, by steam or other heating medium, as is conventional in the art, a very weak bond is formed between the conductors. Alternatively, press rollers or other means may be used, as is also conventional in the art, to positively force or press the separated conductors and the insulation together to form the adhesive umon.

Referring in particular to Figs. 1, 2 and 3, it may be seen that in either case the retainer elements and are clamped by screws into firmly abutting relation to 30 the face of the die body 2. The recesses 15 and 16 in die body 2 are of suflicient depth and the knife holders 55, 70 and 71 of sulficient thickness that a substantially flush surface is presented to the abutting face of either retainer when positioned on the die body.

While the use of the device for the formation of readily severable insulation between the conductors has been described, it is to be noted that conventional, oval type insulated wire may also beformed with the same basic die body and proper choice of interchangeable parts. 40

Referring in particular to Figs. 3, 6, 8 and 11, the die body 2 may be provided with the knife holders 55 properly positioned on dowel pins 12. The knife element is omitted and retainer member 40 is positioned in its proper relation with respect to discharge orifice 7. Machine screws 45 are then passed through apertures 41 and threadedly engaged in the internally threaded bores 14 in die body 2 to clamp the retainer and the knife holders in fixed relation to the die body 2 and orifice 7. As the insulating material is extruded around the plural con- 50 ductors, no slitting or other disturbance of the insulators results and conventional plural strand insulated wire is formed.

Thus, it may be seen, that the invention contemplates the formation of a standard die body having a face so arranged that it may be adapted for use with cooperating interchangeable retainer and slitter or cutting elements or retainer members alone, which in turn, may be used selectively and interchangeably to produce, by means of the same die body, more than one type of insulated orcovered conductor product. In this respect, it is to be noted that the change from one type of production to another may be conveniently and easily accomplished by the simple act of selectively substituting the desired retainer in combination with the desired interchangeable elements on the face of the die body. Thus, the necessity for dismantling of the die and its removal from the extruding machine is obviated.

While this invention has been described and illustrated hereinabove with special reference to preferred embodiments thereof, it is to be understood that changes and modifications may be made therein without departing from the spirit or scope thereof as defined by the appended claims. 7

mam -7 6 We claim: 1. A die apparatus for use with an extrusion apparams and adapted to form plural commonly insulated coiiductors wherein the cross-sectional a'reaof the common insulation between said conductors is interrupted to fa cilitatepartingof said insulati'on between said conductors comprising a cylindrical die body, said die 'body'being provided with a tapered bore extending axially of its longitudinal axis and tapering from end to end, said cylindrical die body further including a planar discharge face, said tapered bore terminating at said discharge face in a generally oval-shaped discharge orifice, said planar discharge face being interrupted by a pair of diametrically arranged, aligned channel-shaped recesses, said recesses being symmetrical about a plane bisecting said ovalshaped discharge orifice transversely of its longer dimension, a plurality of guide pins projecting outwardly from the bottoms of said channel-shaped recesses, said guide pins being symmetrically arranged with respect to said discharge orifice, said pins also having their outer terminal ends terminating in a plane coextensive with the outer surface of said planar discharge face, said die face, said recesses provided therein and said pins being adapted to selectively receive one set of a plurality of sets of insulation interrupting elements.

2. In an extruding apparatus for applying a common insulated covering to plural conductors, and for interrupting said covering so as to provide localized weakened areas thereby facilitating separation thereof, between said conductors, a die body, said die body having a cylindrical outer surface, fiat planar end faces and a tapered internal bore, one of said faces comprising a discharge face, said tapered bore terminating at said face in an oval-shaped discharge orifice, said discharge face further being provided with a pair of channelshaped diametrically aligned recesses, a plurality of guide pins projecting outwardly from said recesses and terminating at the plane in which the planar discharge face lies, said recesses and said guide pins being symmetrically located about said oval discharge orifice, means positioned in said recesses to mold and form the localized weakened areas in said insulated covering, a cylindrical retainer means and bolt means pasing both through said retainer means and said forming means and into said die body thereby maintaining said last two mentioned means in coextensive removable relation on said discharge face, said last two mentioned means being comprised of one complementary group of a plurality of elements adapted to form the insulated covering intovarying configurations.

3. An extruding apparatus as defined in claim 2, wherein said recesses provided in said discharge face receive a pair of generally rectangular slotted blocks, said blocks receiving in turn a generally T-shaped knifelike element, said element bisecting said oval-shaped discharge orifice along its minor axis, said cylindrical retainer means being provided with an oval-shaped aperture complementing that of said discharge orifice, and said blocks being further provided with guide pin apertures receiving said guide pins.

4. An extruding apparatus as defined in claim 2 wherein the recesses provided in said discharge face receive a pair of slotted holder elements having reduced inner edges terminating in a blunt point, said holder elements receiving in turn a pair of knife-like elements which are slidably adjustable longitudinally of said slots, said cylindrical retainer means being provided with a generally figure 8 configured aperture registerable with said ovalshaped discharge orifice and said holder elements being provided with guide pin receiving apertures.

5. An extruding apparatus as defined in claim 3 wherein said retainer means bears against said planar discharge face, said slotted blocks and said knife-like element so 5 as to clamp the holder elements in the recesses provided 8 On said discharge face, and said knife-like element i saigl Refere ces Cites! in the file of this patent Qg b1 t a fi I 4 h UNITED STATES PATENTS nex ruslo appara us as e ne 1 03111; w eree in said retaiper means bears against said plan'a'r discharge 'gg fii a??? 7 face, said slotted blocks and said knife-like elements so 5 3 1 1950 as'to clamp the blocks in said recesses provided on the 2'524829 3 25? i 1 1950 dxscharge face of sad dle body and sald km feh ke ele- 2 COX Jan. 20 1953 ments in said slotted blocks. 

